In the related art, for example, an exhaust gas purification device disclosed in Patent Literature 1 has been known as an exhaust gas purification device for purifying exhaust gas flowing through an exhaust gas channel. The exhaust gas purification device disclosed in Patent Literature 1 includes an injection nozzle (injection device) for injecting urea water (reducing agent) to the exhaust gas, and reduces and purifies NOx in the exhaust gas by using ammonia generated by the injection of the urea water.